The present invention relates to a collapsible bag expander, and more particularly to such a collapsible bag expander, which is made of a patterned cardboard, and which expands automatically to support the collapsible bag in shape after removal of the collapsible bag from the packing material.
In order to support a backpack, travel bag, or any of a variety of collapsible bag in shape for exhibition, stuffing paper or like material is commonly used to stuff the bag. However, it is inconvenient to stuffing a collapsible bag with stuffing material. Further, when collapsing the collapsible bag, the stuffing material must be taken away. In order to eliminate these problems, various bag expander means have been developed. FIGS. 1 and 2 show a prior art bag expander for this purpose. This structure of bag expander is comprised of two folding panels and a stretcher connected between the folding panels. The stretcher has two coupling flaps at two distal ends respectively fastened to a respective coupling hole on each folding panel. This structure of bag expander is not satisfactory in function because it tends to be deformed and, the stretcher tends to be forced away from the coupling hole on each folding panel. FIGS. 3 and 4 show another structure of bag expander according to the prior art. This structure of bag expander comprises two symmetrical expander elements or substantially U-shaped cross section coupled together, and spring means fastened to the expander elements to secure the expander elements in the extended position. The expander elements each have two side panels, and coupling means at the side panels. The coupling means at the side panels of one expander element are respectively fastened to the coupling means at the side panels of the other expander element. The spring means are respectively fastened to the coupled coupling means to secure the expander elements in the extended position. Further, the side panels of the expander elemenets can be folded inwards to collapse the bag expander. This structure of bag expander has less industrial value because it is complicated and expansive.
The present invention has been accomplished to provide a bag expander, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a bag expander, which is simple and inexpensive. It is another object of the present invention to provide a bag expander, which automatically extends out to support the bag in shape after removal of the bag from the packing material. According to one embodiment of the present invention, the bag expander is compirised of a patterned cardboard, which is folded into a three-dimensional configuration to support the bag in shape, and two elastic bands, which secure the patterned cardboard in the folded shape. The patterned cardboard comprises a base panel, the base panel having a top side, a bottom side, and two opposite lateral sides, two opposite side panels extended from the two opposite lateral sides of the base panel, two supporting flaps respectively longitudinally extended from the side panels at a top side, and two coupling flaps respectively transversely extended from two opposite lateral sides of the bottom panel in reversed directions, the side panels each having a hooked portion remote from the supporting flaps, the coupling flaps each having a hooked portion respectively hooked up with the hooked portions of the side panels. The elastic bands are respectively fastened to the coupled hooked portions of the side panels and the coupling flaps to secure the patterned cardboard in the folded shape.